Faith Kroll and her fiancee Jim Marcus climbed on stage in front of about 100 Northwestern University students and demonstrated the use of the motorized sex toy at gathering for a human sexuality class. "It is probably something I will remember the rest of my life," said senior Justin Smith, 21, one of the students who stuck around voluntarily after class when students were told about what they were about to see.

(CBS/WBBM/AP) EVANSTON, Ill. - Faith Kroll and her fiancee Jim Marcus climbed on stage in front of about 100 Northwestern University students and demonstrated the use of the motorized sex toy at a recent gathering for a human sexuality class.

"It is probably something I will remember the rest of my life," said senior Justin Smith, 21, one of the students who stuck around voluntarily after class when students were told about what they were about to see.

Now, the president of the university has demanded an investigation.

In the statement from the school, President Morton Schapiro said he was "troubled and disappointed" and said the teacher exercised "extremely poor judgment."

The Feb. 21 demo was part of the popular class taught by Prof. John Michael Bailey, the Sun-Times is reporting. More than 600 students take the class, which the course description says "will treat human sexuality as a subject for scientific inquiry," reports CBS affiliate WBBM.

"[Kroll's] boyfriend did the penetration on her," said Ken Melvoin-Berg, who narrated during the class. He operates the "Weird Chicago Red Light District Sex Tour," the station reported.

Bill Yarber, a researcher at Indiana University's Kinsey Institute and author of the widely used textbook "Human Sexuality: Diversity in Contemporary America," said he's never heard of a naked woman being brought to orgasm in front of a class of students.

"There's certain boundaries of things, I think, that are acceptable and that would certainly be pushing that," he said, according to WBBM.